1. 构造函数
2. CloseEvent
3. 属性
4. bubbles
5. cancelable
6. code
7. composed
8. currentTarget
9. defaultPrevented
10. eventPhase
11. hashCode
12. isTrusted
13. matchingTarget
14. path
15. reason
16. runtimeType
17. target
18. timeStamp
19. type
20. wasClean
21. 方法
22. composedPath
23. noSuchMethod
24. preventDefault
25. stopImmediatePropagation
26. stopPropagation
27. toString
28. 操作符
29. 操作符 ==